Apparatus for manufacturing pneumatic-tire casings



I W. LERCH. -APPRRAT$ FOR MANUFACTURING PNEUMATIC TIRE CASlNGS.

' APPLICATION HLED 001.25, 1920.

1,331,371 5. Patented 31111614, 1921., i

Wm. G. lelcil,

swue/wtoz PATENT omen.-

WILLIAIMG. LEEGH,. OiE Axnomonro, AssrNoR-T'ro rni zj lvnra TIRE emnmm "commit, o'nmoeanorm, oHro'; con on OHIQ ,IAPI'ARATUS .1303 mnnunnczrun ne rivn mua'rrcflmn CASINGS.

i sgeeificationiof ikttersl atentfl. J f gg Application flied-camber- 25,1920, sw rm. 419,173.

particularly, cord tires, the tirefcasihg is builtup, an air bag is then placed within the casing andit is placed within the cavity of a tire mold and the air bagis'inflated'to stretch and compact the casin duringvul canizatio'n. Air bags of this character must possess a certain degree of elasticity and 'are usually composed of rubberreinforced with textile fabric. An air bag mustfbe-subjected to a vulcanizing heat, each time a tire is cured thereon'and, after a short period of use, it becomes ermanently' enlarged and wrinkles and fol s back upon-itself causing buckles in the casing and greatly reducing the strength and usefulness thereof. This results in a considerable financial loss, not only because of an inferior less valuable product,.but because the airbag, which is of expensive construction, must be discarded.

It is therefore an object ofthis invention to provide a protective, expansibleshea'th of simple, economical construction which in use may be interposedbetween the interior surface of a pneumatic tire casing and an air bag and which when so used will produce a more perfect product and will greatly lengthen the life of the air bag used in conunction therewith.

A further object is to provide a protective cover for an air bag which will expand both laterally and longitudinally when fluid pressure is introduced within the bag and which will uniformly distribute the pressure exerted by said fluid.

A still further object is to provide a means whereby tires may be vulcanized on an air bag without the use of highly skilled labor and which will produce a product having a smooth interior surface and consequently, a relatively better product at a relatively lower "cost' than can be produced by any method heretofore known. v "The above objects are accomplished and additionalends are attained by the novel construction, combination and arrangement of parts herein described andshown in the accompanying drawings wherein I have illustrated a preferred embodiment of the invention, it being understood that the inventionis capable of various adaptations and that changes, va'riations'and modifications may be made or substitutions resorted towhich'come within the scope ofthe claims hereunto appended.

In the drawingsfin which similar numerals-of reference are employed to designate corresponding parts throughout the several views,

tionalview-of a tire casing, showing an air bag positioned therein with my new and improved sheathiinterposed therebetween.

' Fig. 2 is a transverse, sectional view taken as ,indicatecl by the lines 2-2 of Fig. 1.

Fig. '3 is a perspective view of a portion of a sheath constructed in accordance with this invention showing the manner in which "the several sections arev assembled in end to end abutment.

F ig. 4 is a' transverse sectional view of a tire vulcanizing mold showing a tire casing therein with an airbag within the casing and illustrating particularly a manner of using my newjprotective sheath. Proceeding now to a detailed description of the invention and particularly to a description of'the embodiment thereof illustrated'in the drawings, the numeral 7 is used generally to denote an annular sheath preferably formed of sheet metal and shaped to conform to the contour of the interior surface of a pneumatic tire casing. The said sheath 7 is made up of a plurality of separable sections 7, 7", 7, 7 and 7 adapted when placed in overlapping end to end abutment to form an annulus which will expand both laterally and longitudinally. One end of each of said sections is provided with an overlapping knife-like edge 8 and the other end thereof with an overlapped knife-like edge 9 so that when placed in end to end abutment the sheath has a smooth, continuous interior and exterior surface.

The numeral 5 is used to denote an air I Figure I is a. longitudinal, central, 'secbag which may be of ordinary or improved construction and which is provided with an inflation stem 10. The numeral 6 is used to indicate a pneumatic tire casing and the numeral 11 the ordinary two part mold in which said casing is vulcanized.

In use, the tire 6 is built up on a solid core. The core is then removed and the sections 7, 7", 7, 7 and 7 are placed within the cavity of the casing in end to end abutment as shown in Figs. 1 and 2, An air bag 5 is then placed within the sheath 7 and the rings 12 and 13 are secured on each side of the inner circumferential edges of the 7 casing. The inflation stem 10 is then connected to an air compressor or other source of air supply and the air bag 5 is inflated. As the air bag 5 expands the inner circumferential edges of the sheath 7 will be forced laterally apart and the end 8 ofieach section will slide on the end 9 and the sheath will thus be expanded both laterally and longitudinally.

In practice, the air bag may thus be secured within the tire and the tire secured within the cavity of the two part mold -11. The bag may then be inflated and the casing stretched and compacted. between the sheath 7 and the interior surface of the mold 11.

It will thus be seen that I have provided a simple, effective means whereby an air bag may be used to expand a tire during vulcanization and'which when so used will produce a smooth, continuous surface on the inrterior of a casing vulcanized thereon. 7

Having thus described my invention what I claim as new and desire to secure by Letters-Patent is I l. A protective sheath of the class described, comprising a plurality of sections of sheet metal adapted when placed in overlapping end to end abutment to form an annulus, each of said sections being arched lat erally and longitudinally'to conform to the interior surface of a pneumatic tire casing.

2; A protective sheath of the class describedcomprising an annulus of sheet metal shaped to conform to the interior contour of .a pneumatic tire casing, said annulus comprising a plurality of separable sections, the end of each section terminating in a knifelike edge, each section adapted when brought comprising an inflatable annular tube and a coveringtherefor, said covering comprising a plurality of separable sections composed of sheet metal, arched laterally and longitudinally in conformity with the interior surface of a pneumatic tire casing.

4. In combination with a pneumatic tire casing, an annular inflatable air bag therein, a protective sheath interposed therebetween, said sheath comprising a plurality of separable sections, adapted when placed in overlapping end to end abutment to conform to the contour of the interior surface of said casing, and means to confine said air bag in said casing.

5,. In combination with a tire vulcanizing mold, a tire casing therein, an inflatable tube in said casing, and a metallic sheath interposed between said tube and the interior surfaceof said casing, said sheath comprising. a plurality of separable sections adapted when placed in overlapping end to end abutment,

toform an annulus conforming in shape to the interior surface of saidcasing and being substantially coextensive therewlth. V

6. A protective sheath of the class described, comprising a plurality of sections of sheet material adapted when placed in overlapping end to end abutment to form an annulus conforming in shape to the interior surface of a pneumatic tire casing. o

7. In combination with an expansible annular air bag ofthe class described a protective sheath therefor, said sheath comprising a plurality ofrsimilar sections of substantially rigid sheet material adapted when placed on overlapping end to end abutment to cover the interior surface of a pneumatic. tire casing, i

In testimony whereof I have hereunto set my hand, i

WILLIAM G. LERCH. 

